Gαs, a subunit of the heterotrimeric G protein, has a crucial role in mediating the signal transduction from G protein coupled-receptor (GPCR) into intracellular proteins. This cascade process is accompanied by conformational change of Gαs protein such as binding to β2AR as well as contributing to GDP/GTP exchange. We investigated dynamic features of Gαs based on the X-ray crystal structure of β2AR-Gαs complex and elastic network based simulation was performed to reveal the whole conformational change pathway of β2AR-Gαs complex. The normal mode results strongly propose that N terminus of Gαs initially binds to the activated β2AR and then C terminus binding is followed. These two binding events would break the densely connected GDP pocket site located between two Gαs subdomains (Ras-like GTPase and α-helical domain), leading to the increase of the GDP solvent-accessible surface area. We also identified a flexible hinge point of switch 1 linker region from the proposed large swing motion of Gαs between closed and open conformation. B-factor comparison between GDP and GTP binding to Gαs indicates that GTP binding much more suppresses the mobility of both switch 1 and switch 2 regions, while both N and C termini vibrate more actively. It facilitates reorientation of Gαs to its initial closed form in order to complete the entire cycle of conformational change. This atomistic simulation not only confirms various experimental observations regarding β2AR-Gαs complex but also newly reveals the binding affinity of Gαs termini for β2AR.